There is a need for research that can help better predict risk and prevent suicide among adolescent youth. Rates of suicidality, a strong predictor of suicide, are higher among adolescent girls compared to boys, and highest among sexual minority girls (girls who endorse same-sex romantic attraction, behavior or identity). This study tests an innovative model of suicide risk in a sample of sexual minority and nonminority adolescent girls that integrates neurobehavioral and interpersonal vulnerabilities. Specifically, the model posits that neural sensitivity to social rejection, when occurring in the presence of peer rejection, increases risk for suicide. This proposed K01 bridges the candidate's prior training in interpersonal risk for depression and developmental psychopathology, with new training in affective neuroscience and suicide risk. This training will uniquely position the candidate to investigate the development of negative valence systems, with an emphasis on affective sensitivity to social rejection, and associations with suicidality. Thus, the proposed study will be the first in a larger program of research that will contribute to NIMH research priorities, such as Strategic Objective 2, by investigating how individual differences in biologic and social/environmental factors contribute to heterogeneity in the development of suicide risk in diverse populations. Specifically, the candidate plans to follow the proposed study with larger longitudinal studies using multiple methods and repeated assessments of neurobehavioral and interpersonal vulnerability for suicide during the adolescent developmental period to examine 1) how pain related neural circuitry underlying affective sensitivity to social rejection may be associated with suicide risk, and 2) interpersonal factors (e.g., interpersonal rejection) that may contribute to and strengthen sensitivity to social rejection over time within the context of social and pubertal changes in adolescence. The candidate will also be positioned to investigate etiological models explaining elevated suicide risk among sexual minority youth. This program of research is expected to advance the field by improving the ability to predict risk for suicide among vulnerable youth, and to identify targets for intervention during optimal developmental windows. To achieve these career objectives, the candidate will receive training in developmental affective neuroscience, neuroimaging methods, and theory and research on development of suicide risk in adolescence, including sexual minority youth. She has an ideal mentorship team within an optimal scientific training environment to provide the requisite training for her to meet her career goals. Dr. Jennifer Silk is an expert on development of social-emotional processing from childhood into adolescence. Dr. Mary Phillips has significant expertise in affective neuroscience and fMRI methods, and neural underpinnings of emotional reactivity and regulation. Dr. Michael Marshal provides expertise on suicidality disparities between sexual minority and nonminority youth. Additional mentorship and support from consultants will provide training in the role of pain neural circuitry underlying the affective experience of social rejection (i.e. social pain, Dr. Naomi Eisenberger), and the development of suicide risk in adolescents (Dr. David Brent) and new methods to assess suicide risk (Dr. Matt Nock).